Principal Investigator/Program Director (Last, first, middle): Grayck, Eva, Nozik RESEARCH &RELATED Other Project Information 1. * Are Human Subjects Involved? m Yes l No 1.a. If YES to Human Subjects Is the IRB review Pending? m Yes m No IRB Approval Date: Exemption Number: 1 2 3 4 5 6 Human Subject Assurance Number 2. * Are Vertebrate Animals Used? l Yes m No 2.a. If YES to Vertebrate Animals Is the IACUC review Pending? m Yes l No IACUC Approval Date: 05-01-2006 Animal Welfare Assurance Number A3269-01 3. * Is proprietary/privileged information m Yes l No included in the application? 4.a.* Does this project have an actual or potential impact on m Yes l No the environment? 4.b. If yes, please explain: 4.c. If this project has an actual or potential impact on the environment, has an exemption been authorized or an environmental assessment (EA) or environmental impact statement (EIS) been performed? m Yes m No 4.d. If yes, please explain: 5.a.* Does this project involve activities outside the U.S. or m Yes l No partnership with International Collaborators? 5.b. If yes, identify countries: 5.c. Optional Explanation: 6. * Project Summary/Abstract 7629-project_summary.pdf Mime Type: application/pdf 7. * Project Narrative 5524-Project_Narrative.pdf Mime Type: application/pdf 8. Bibliography &References Cited 4290-References_RO1.pdf Mime Type: application/pdf 9. Facilities &Other Resources 0096-RESOURCES.pdf Mime Type: application/pdf 10. Equipment 2290-Equipment.pdf Mime Type: application/pdf Tracking Number: Other Information Page 5 OMB Number: 4040-0001 Expiration Date: 04/30/2008 Principal Investigator/Program Director (Last, first, middle): Grayck, Eva, Nozik PROJECT SUMMARY/ABSTRACT PA vascular remodeling with pulmonary hypertension is a life-threatening complication in infants and children with hypoxic lung diseases. A further understanding of this process is essential to develop new strategies aimed at reducing the severity of pulmonary hypertension in these individuals. Accumulating evidence indicates that reactive oxygen species (ROS), including superoxide (O2-) generated via NADPH oxidase, contribute to vascular remodeling. Extracellular oxidant/antioxidant homeostasis is maintained by the extracellular isoform of superoxide dismutase (EC-SOD), which is highly expressed in the vessel wall. The proposal tests the hypothesis that hypoxia disrupts the balance between the production of extracellular O2- by NADPH oxidase and its clearance by EC-SOD in the PA. We further hypothesize that excess extracellular O2- generated in the hypoxic lung upregulate a hypoxia-inducible and redox-sensitive transcription factor, early growth response-1 (Egr-1), which, in turn, stimulates Egr-1-responsive genes important in causing neonatal chronic hypoxia-induced pulmonary vascular remodeling and pulmonary hypertension. Aim 1 will use PA segments isolated from chronically hypoxic calves and mice and in vitro pulmonary artery vascular cells isolated from the neonatal calf to evaluate production of reactive oxygen species and expression and activity of EC-SOD. Aim 2 will use chronically hypoxic mice overexpressing and lacking EC-SOD as well as mice lacking gp91phox subunit of NADPH oxidase to provide in vivo molecular and pharmacologic evidence that extracellular O2- regulates critical hypoxia-responsive genes and contributes to chronic hypoxia-induced pulmonary vascular remodeling and pulmonary hypertension in the developing lung. To complement this model, in Aim 3, we will use the PA adventitial fibroblast isolated from the neonatal calf as a highly relevant model system for in vitro experiments to test the effects of hypoxia-induced extracellular O2- on the expression of the redox-sensitive transcription factor Egr-1. The study of chronic hypoxia as a stimulus for pulmonary vascular remodeling and pulmonary hypertension is compelling, as hypoxia is a common feature of diverse lung diseases. Thus, by advancing our knowledge base and testing new therapeutic approaches in animal models, we will provide a solid foundation for future human clinical trials in a range of scenarios associated with hypoxic lung diseases to improve health outcome for patients with these difficult and serious problems Project Description Page 6